package d1203.r2118.num06;

import java.util.Map;
import java.util.Set;
import java.util.TreeMap;

public class Demo02Map {
    public static void main(String[] args) {
        Map<Integer,String> map = new TreeMap();
        map.put(1,"zhangsan");
        map.put(2,"lisi");
        map.put(3,"wangwu");
        map.put(4,"zhaoliu");
        Set<Integer> set = map.keySet();
    }
}
